And no, many Southern Chinese cities still have complex layouts in their historical districts (e.g. Suzhou, Nanjing, Yangzhou). Just check them out on Google Maps. No one in their right minds will build anything without following a grid pattern at least loosely in the post-WWII era. Having reasonably wide roads to accommodate traffic is just basic urban planning. Many rapidly growing Chinese cities suffer from chronic traffic congestion because even the roads built in the 90s don't have enough capacity to handle so many cars. Maybe the "eight-lane highways" were needed because of that?
Cities that had the opportunity to rebuild (like Chicago after the 1871 fire) make use of grids.
Urban planners just like big wide straight roads and with automobiles they can really indulge themselves. They look neat and tidy on a plan and impressive in real life. Building for officials and planners, not for living. That said the party-state is very much alive to the possibility of revolt and I’m sure some people thought about the military implications of urban planning but I’d say the primary motivation was ease of planning and building more than crowd control concerns. A competent military force would be quite capable of crushing an urban revolt even if both sides were armed with nothing but rifles. Professionals beat amateurs at everything and when the professionals have not just drill, discipline and training on their side but overwhelming fire power, air support and better communications the difference in capabilities becomes comical.
https://www.citymetric.com/fabric/paris-barricades-how-hauss...